The present invention relates to an apparatus for inspecting microscopic contamination, defects, and haze existing on the surfaces of samples such as semiconductor substrates.
In manufacturing lines for semiconductor substrates, thin-film substrates, and the like, the defects and contamination existing on the surfaces of semiconductor substrates, thin-film substrates, or the like, are inspected to maintain or improve respective product yield rates. For example, before circuit patterns are formed on samples such as semiconductor substrates, these samples require the detection of microscopic surface defects and contamination of 0.05 microns or less in diameter. In order to detect these microscopic surface defects and contamination, such a conventional inspection apparatus as described in Patent Document 1 (JP-H09-304289-A) irradiates the surface of a sample with a laser beam condensed to several tens of microns, and acquires/detects the light scattered from defects or contamination. In addition, in conventional techniques for discriminating the kinds of defects, the directionality of the light scattered from a defect is discriminated by detecting the scattered light from multiple directions, as in Patent Document 1 (JP-2001-255278-A).
For even more accurate detection of defects and/or contamination, it is important to reduce the amount of light scattered by the roughness (haze) existing on the substrate surface. Techniques for implementing the reduction are described in Patent Document 3 (U.S. Pat. No. 6,034,776), Patent Document 4 (U.S. Pat. No. 6,639,662), and Patent Document 5 (U.S. Pat. No. 7,002,677).